{"id":"CVE-2026-31721","state":"PUBLISHED","title":"usb: gadget: f_hid: move list and spinlock inits from bind to alloc","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_hid: move list and spinlock inits from bind to alloc\n\nThere was an issue when you did the following:\n- setup and bind an hid gadget\n- open /dev/hidg0\n- use the resulting fd in EPOLL_CTL_ADD\n- unbind the UDC\n- bind the UDC\n- use the fd in EPOLL_CTL_DEL\n\nWhen CONFIG_DEBUG_LIST was enabled, a list_del corruption was reported\nwithin remove_wait_queue (via ep_remove_wait_queue). After some\ndebugging I found out that the queues, which f_hid registers via\npoll_wait were the problem. These were initialized using\ninit_waitqueue_head inside hidg_bind. So effectively, the bind function\nre-initialized the queues while there were still items in them.\n\nThe solution is to move the initialization from hidg_bind to hidg_alloc\nto extend their lifetimes to the lifetime of the function instance.\n\nAdditionally, I found many other possibly problematic init calls in the\nbind function, which I moved as well.","publishedAt":"2026-05-01T14:14:23.492Z","updatedAt":"2026-05-11T22:14:28.436Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"13440c0db227c5db01da751ed966dde4cdd2ea18","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"de93e0862169b5539e00c2b9980b93fd80c37c0d","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"81aee4500055876883658b024b6fb61801afe134","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"8ec6a58586f195a88479edcdb0b8027c39f12d03","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"f7d00ee1c8082c8a134340aaf16d71a27e29c362","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"5d1bb391ceeebb28327703dd07af8c6324af298f","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"26a879a41ed960b3fb4ec773ef2788c515c0e488","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"4e0a88254ad59f6c53a34bf5fa241884ec09e8b2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/function/f_hid.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.19","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.169","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.135","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/function/f_hid.c"]}],"references":["https://git.kernel.org/stable/c/13440c0db227c5db01da751ed966dde4cdd2ea18","https://git.kernel.org/stable/c/de93e0862169b5539e00c2b9980b93fd80c37c0d","https://git.kernel.org/stable/c/81aee4500055876883658b024b6fb61801afe134","https://git.kernel.org/stable/c/8ec6a58586f195a88479edcdb0b8027c39f12d03","https://git.kernel.org/stable/c/f7d00ee1c8082c8a134340aaf16d71a27e29c362","https://git.kernel.org/stable/c/5d1bb391ceeebb28327703dd07af8c6324af298f","https://git.kernel.org/stable/c/26a879a41ed960b3fb4ec773ef2788c515c0e488","https://git.kernel.org/stable/c/4e0a88254ad59f6c53a34bf5fa241884ec09e8b2"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31721.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31721","state":"PUBLISHED","datePublished":"2026-05-01T14:14:23.492Z","dateUpdated":"2026-05-11T22:14:28.436Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.134Z"},"containers":{"cna":{"title":"usb: gadget: f_hid: move list and spinlock inits from bind to alloc","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_hid: move list and spinlock inits from bind to alloc\n\nThere was an issue when you did the following:\n- setup and bind an hid gadget\n- open /dev/hidg0\n- use the resulting fd in EPOLL_CTL_ADD\n- unbind the UDC\n- bind the UDC\n- use the fd in EPOLL_CTL_DEL\n\nWhen CONFIG_DEBUG_LIST was enabled, a list_del corruption was reported\nwithin remove_wait_queue (via ep_remove_wait_queue). After some\ndebugging I found out that the queues, which f_hid registers via\npoll_wait were the problem. These were initialized using\ninit_waitqueue_head inside hidg_bind. So effectively, the bind function\nre-initialized the queues while there were still items in them.\n\nThe solution is to move the initialization from hidg_bind to hidg_alloc\nto extend their lifetimes to the lifetime of the function instance.\n\nAdditionally, I found many other possibly problematic init calls in the\nbind function, which I moved as well."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"13440c0db227c5db01da751ed966dde4cdd2ea18","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"de93e0862169b5539e00c2b9980b93fd80c37c0d","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"81aee4500055876883658b024b6fb61801afe134","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"8ec6a58586f195a88479edcdb0b8027c39f12d03","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"f7d00ee1c8082c8a134340aaf16d71a27e29c362","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"5d1bb391ceeebb28327703dd07af8c6324af298f","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"26a879a41ed960b3fb4ec773ef2788c515c0e488","versionType":"git"},{"version":"cb382536052fcc7713988869b54a81137069e5a9","status":"affected","lessThan":"4e0a88254ad59f6c53a34bf5fa241884ec09e8b2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/function/f_hid.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.19","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.169","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.135","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/function/f_hid.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/13440c0db227c5db01da751ed966dde4cdd2ea18"},{"url":"https://git.kernel.org/stable/c/de93e0862169b5539e00c2b9980b93fd80c37c0d"},{"url":"https://git.kernel.org/stable/c/81aee4500055876883658b024b6fb61801afe134"},{"url":"https://git.kernel.org/stable/c/8ec6a58586f195a88479edcdb0b8027c39f12d03"},{"url":"https://git.kernel.org/stable/c/f7d00ee1c8082c8a134340aaf16d71a27e29c362"},{"url":"https://git.kernel.org/stable/c/5d1bb391ceeebb28327703dd07af8c6324af298f"},{"url":"https://git.kernel.org/stable/c/26a879a41ed960b3fb4ec773ef2788c515c0e488"},{"url":"https://git.kernel.org/stable/c/4e0a88254ad59f6c53a34bf5fa241884ec09e8b2"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T22:14:28.436Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.19","versionEndExcluding":"5.10.253"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.19","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.19","versionEndExcluding":"6.1.169"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.19","versionEndExcluding":"6.6.135"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.19","versionEndExcluding":"6.12.81"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.19","versionEndExcluding":"6.18.22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.19","versionEndExcluding":"6.19.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.19","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}